The present invention relates to automotive transmissions and in particular to remanufacturing of a transmission pump for use in a remanufactured automotive transmission.
The automotive transmission may experience a failure and, subsequently, be removed from service, remanufactured, and returned to service. Any abnormally worn parts are repaired or replaced during remanufacturing. For example, if the pump pocket bore is worn, the bore may be machined to a larger diameter and a correspondingly larger diameter set of pump gears installed.
Also during remanufacturing of the transmission, flow rate through the pump may be increased. The pump may be remanufactured to increase an amount of transmission fluid that is pumped for every revolution of the pump. For example, the larger diameter set of pump gears may have pump chambers with larger radial areas. Alternatively, an unchanged diameter set of pump gears having larger radial area pump chambers may be used. Alternatively, a larger diameter set of pump gears having unchanged radial areas of the pump chambers may be used. Alternatively, a set of pump gears having the same diameter but larger radial areas may be used with the same diameter but with larger radial areas of the pump chambers or larger diameter pump gears may be used without changing the radial areas of the pump chambers. However, it is desirable for flow characteristics at the inlet and outlet ports to be maintained when the flow rate is increased. Original gears kept because the pump bore is not worn maintains flow characteristics, but does not increase flow rate. Using the larger diameter gears with larger radial areas increases flow rate, but may not maintain flow characteristics. Furthermore, the larger diameter gears have a greater circumferential area which reduces efficiency of the pump.